Animal Nutrition: Overview of Feedstuffs and Terminology in Livestock Diets

mineral supplements

13 known to be required (in swine--humans, swine, and cattle are very similar in these requirements). Include macrominerals and trace minerals (microminerals).

forage

Vegetative part of the plant. Often used interchangeably with "roughage".

ruminants

Vitamins A, D, and E the main concern in these animals. Microorganisms synthesize K, C, and B vitamins.

swine

Vitamins A,D, and E, riboflavin (used for FAD), niacin, pantothenic acid, B12, and choline (nerves, not really a vitamin) are the main concern in these animals.

1. Feed into diet (chickens, etc.) 2. Others self-regulate (as a block, etc.)

Ways to provide supplements.

digestible energy

What "DE" stands for in NRC table.

metabolizable energy

What "ME" stands for in NRC table.

net energy

What "NEg" stands for in NRC table.

net energy for maintenance

What "NEm" stands for in NRC table.

International Feed Number

What IFN stands for. Shows which of the eight categories the food falls into (first digit indicates which category), and then specifically which feed it is.

MGA

A hormone additive that suppresses the estrus cycle so animals can eat instead of exhibiting sexual behavior.

nutrient partitioning agents

What implants work as. For example, an implant can make the animal use more protein, so they are leaner.

The amount of fermentation is directly proportional to the quality of the silage. The more lactic acid that is present, the less oxygen that has penetrated to decrease the fermentation and nutrients, so the better the silage.

What makes "good" silage.

Drop in pH.

What stops the ensiling process.

bloat

When air is trapped in the rumen and the animal can't belch out CO2.

protein supplements

Feeds containing more than 20% protein or protein equivalent (high in nitrogen content). Most contain 20-50% protein (thus, half or more is a source of energy, but not considered an energy feed).

roughages

Feeds generally high in fiber (cellulose), less digestible, and lower in energy. Animals consuming high-THIS diets don't gain as fast as those consuming high-concentrate diets.

concentrates

Feeds that are generally high in energy, low in fiber, and are usually highly digestible. Produce rapid gains.

silages and haylages

Fermented forages stored under anaerobic conditions. Undergo anaerobic fermentation--the microbes partially digest soluble sugars (such as starch), which makes the forage more digestible than the original forage. The entire aerial part of the plant is used. Used as winter feed.

ether extract

On NRC table, indicates % fat in the feed.

ash

On NRC table, indicates total minerals in the feed. This column does not have a lot of meaning.

crude fiber (CF)

On NRC table, indirectly indicates the amount of cellulose.

crude (as in protein)

On NRC table. Boil feed sample in concentrated sulfuric acid to find the amount of nitrogen, and then use TOTAL nitrogen to determine protein. It's a rough estimate because a little nitrogen comes from sources other than protein. "True protein" is an absolute measure of protein.

"high-energy" or "high-grain"

Other names for high-concentrate diets.

silage

Preserved pasture materials that have been fermented that are stored under anaerobic conditions, and are between 35-40% DM. The microorganisms that do the fermentation are already living in the grass.

-Compudose (estradiol-17 beta) -Ralgro (most often used implant) -Synovex-S, -H, -C (steer, heifer, calf, respectively)

Specific examples of implants.

-Soybean meal -Cottonseed meal -Linseed meal -Peanut meal -Meat meal -Fish meal -Urea (no protein in it, but the nitrogen is used by the animal to make protein) -Brewer's grains (very high in protein and fiber after fermentation).

Specific feed types that fall into the category of protein supplements.

-Cereal grains (corn, wheat, oats, barley, sorghum grain, rye). -Mill by-products (corn gluten, bran). -Whole cottonseeds. -Fats. -Oils.

Specific feed types that fall into the energy feeds category.

-Hay -Straw -Fodder (aka stover) -Hulls -Shells -Pasture and range crops -Some silages

Specific feeds that fall into the dry forages and roughages category.

Cereal grains (corn, milo = sorghum, grain, wheat, oats, barley), oil meals (soybean meal, cottonseed meal, linseed meal), molasses, and dried milk products.

Specific feeds that fall under the category of concentrates.

Legume hays, grass hays, straws (from production of seed and grain), silage, stover, and fresh grass.

Specific feeds that fall under the category of roughages.

-Ionophores (Rumensin and Bovatec) -Bloat control (poloxalene) -Anthelmintics -Drugs/antibiotics -Hormones -Flavoring agents

Specific types of additives added to feed.

1. Dry forages or dry roughages. (Roughage) 2. Pasture and range plants. (Roughage) 3. Silages and haylages. (Roughage) 4. Energy feeds. (Concentrate) 5. Protein supplements. (Concentrate) 6. Mineral supplements. (Concentrate) 7. Vitamin supplements. (Concentrate) 8. Additives. (Concentrate)

The 8 IFN feed categories.

Keeps as much of the nutrients in as possible.

The purpose of fermenting silage.

-Ca (often added) -P (often added) -Na and Cl (salt, often added) -Mg (needed for ATPase--nerve transmission and muscle contraction) (sometimes added) -K -S (component of AAs) (sometimes added)

The required macrominerals. Listed as % of diet.

-Cu -I -Fe -Mn -Se (essential and toxic; needed for RBCs) -Zn -Co (depends on species--needed in ruminants and possibly horses; needed for vitamin B12)

The required trace minerals (microminerals). Listed as ppm or mg/kg of diet. Deficiencies of these are most likely found in monogastrics.

-F (structure of bones and teeth, can also be toxic) -Mo (may or may not actually be required) -Cr (found in the air)

The requirements of animals for these minerals are not well established.

1. Water 2. Protein 3. Fat 4. Vitamins 5. Minerals 6. Carbohydrates

The six classes of nutrients.

dry forages and roughages

High in fiber, low in digestible nutrients/digestibility, low in energy. Greater than 18% crude fiber.

silages and haylages

High-moisture corn (harvested prior to maturity at 25-30% moisture) and reconstituted milo are classified as THIS in the International Feed Nomenclature system.

Feeds in a category have similar feeding values based on nutrient composition.

How feeds are sorted into the 8 IFN categories.

Store in a silo or trench where bacteria cannot infiltrate so the fermentation process can continue.

How silage is preserved.

roughage

A course, bulky feed. Often used interchangeably with "forage".

implants

A substance that is implanted into the body for the purpose of growth promotion or controlling some physiological function. Usually located under the skin of the ear and slowly release hormones. It is against the law to inject meat with hormones. All must be approved as safe and effective by the FDA; heavily tested before put on the market. Labels must be read and followed!

poloxalene

Additive. Controls bloat by reducing surface tension of the compounds in the rumen so the animal can belch out CO2.

flavoring agents

Additives that encourage food intake.

ionophores

Additives. Rumensin is the most used. These alter microbial fermentation in the rumen. The rumen is anaerobic. Inside it, acetic acid (2C, the most produced), propionic acid (3C, the second most produced), and buytric acid (4C, the least produced) are produced, and are then broken down into CO2 and O2. THESE cause production of less acetic acid and more propionic acid because propionic is used more efficiently. So, the animals eat less but gain the same. Also prevent bloat. Rumensin is used as a coccidiostat.

true protein

An absolute (not crude) measure of protein in a feed.

Compudose (estradiol-17 beta)

An implant. A pellet under the skin that stimulates muscle production and slows down fat deposition.

energy feeds

Concentrates. Feeds high in energy (greater than 70% TDN) and low in fiber (less than 18% CF, more starch, less cellulose), less than 20% protein. Highly digestible.

stover

Corn stalks. A type of roughage.

anthelmintics

Dewormers (additives). Worms cause intestinal scarring, and absorption can't occur where there is scarring.

-Silage: 35-40% DM (60-65% water) -Haylage: 40-60% DM (40-60% water)

Dry matter % (and % water) in silage and haylage, respectively.

1. Origin (species, common name, chemical formula). 2. Part fed to animals (grain, seed, aerial part). 3. Processing (ground, steamed, fresh, silage, hay). 4. Stage of maturity (pre-bloom, mature). 5. Cutting (Cut 1, Cut 2). 6. Grade (44% protein, grade 2, chemically pure).

Each feed name (after the category is established) contains one or more of THESE six descriptors.

additive

Enhance intake and improve flavor, but do not add nutrients.

magnesium (Mg)

Forages grow so rapidly in the spring that they don't pull THIS mineral from the soil, so a supplement is needed in the spring. Causes shaking and rigor in cows because the muscles can't contract.

commercial mineral mixes

Frequently do not meet the needs when used (one size does not fit all). Often have excesses of some minerals but are deficient in others. However, usually the best because most people do not have the equipment (requires a special mixer) or knowledge to mix minerals properly. There are interrelationships among minerals--too much of one can tie up another and cause a deficiency.

soilage (greenchop)

Green forage crops that are cut and carried to feed animals grazing on unproductive pastures, in order to supplement their diets. Commonly used crops include clovers and alfalfa.

pasture and range plants

Includes all forage feeds either not cut (including feeds cured on the stem) or cut and fed fresh (greenchop or soilage). Grazed plants that are either growing or dormant. -Quality depends on species and stage of maturity.

additives

Nonnutritive substances which when added to feed will improve feed efficiency and/or production of animals.

horses

Not much research data on vitamins in these animals. -Vitamin A: no problem with green grass and good hay, otherwise supplementation advised. -Vitamin D: Supplement if kept indoors or sunlight erratic. -Vitamin E: No problem with fresh forages and quality hay. Grains are low. -Vitamins C and K: Synthesized by cecal organisms. -Riboflavin and Niacin: Suggested if do heavy work.

vitamin supplements

Tend to get reused, so only needed in minute amounts. Feed content varies: affected by species, part of plant, harvesting, storage, processing. Easily destroyed by heat, sunlight, oxidation, and mold growth.

acetic acid and lactic acid

The acids produced during the ensiling process.

-Silage is fermented and stored under anaerobic conditions. -Soilage is cut and brought directly to the animal.

The difference between soilage (greenchop) and silage.

pH 4-5

The ideal pH for fermentation of silage. A higher pH leaves a bad taste and less nutrients.

1. Cut the pasture when the grasses are at the highest nutrient levels (usually just before fully mature). Important because nutrients are lost during preservation, so as many nutrients as possible need to stay in the feed. 2. Leave grass in the field a few hours so it wilts and loses moisture. Important because it wilts to the moisture level that allows for optimum fermentation. (If left out too long, will dry out or get rained on, which decreases fermentation and amount of nutrients.) 3. Chop into even smaller pieces and compact (if stored in a pit, tractors are driven over until firm; if stored in bales, baling machines compact.) Important because compaction gets out as much oxygen as possible, so microorganisms have optimum anaerobic environment. 4. Seal compacted grass with plastic. Important because it keeps oxygen out.

The steps in silage making, and why each step is important.

1. Temperature increases because of ongoing respiration (aerobic fermentation). 2. When the oxygen is depleted, Enterobacteria (hetero-fermentative bacteria) perform anaerobic fermentation. 3. Then, other bacteria (homo-fermentative) drop the pH and temperature. 4. Temperature stabilizes and more lactic acid is produced to lower the pH. 5. Fermentation process continues in a stable manner as long as oxygen does not penetrate the silage until pH has dropped the correct amount.

The steps of the ensiling process.

antibiotics

These additives are given to cattle for the first few weeks in a new home to help prevent disease.

protein supplements

These are technically "concentrates", but normally we don't include them as energy feed because they are too expensive, and also because they have a lot of protein, which leads to extra nitrogen being excreted, which is bad for the environment.

corn and milo

When these two crops are made into silage, the whole plant (stalk and grain) is used (allows you to feed more livestock per acre). Also, the silage of these two crops is considered a concentrate rather than a roughage because they are high-energy due to the stalk.

Lactic acid, because it is very effective at dropping the pH, which helps preserve the silage.

Which acid is most desirable during the ensiling process, and why.